Protective container

ABSTRACT

A protective container, such as a protective bag, comprising a sealable aperture defined by opposing first and second flexible sheets which are joined to each other by seals at either side of the aperture, such that the aperture is closable by bringing the first and second flexible sheets into contact with each other across the width of the aperture, wherein the inward facing surface of the first sheet comprises an adhesive strip which extends across the width of the aperture and is covered by a release liner such that when the release liner is removed, the aperture is sealable by bringing the adhesive strip into contact with an opposing part of the second flexible sheet across the width of the aperture, wherein the release liner does not extend into the seal between the first and second flexible sheets at either side of the sealable aperture. The protective container is typically waterproof and can be used to protect articles from damage by water, such as rain water or flood water.

FIELD OF THE INVENTION

The present invention relates to the field of protective containers, such as protective bags, for protecting articles from damage by liquids, such as flood water.

BACKGROUND TO THE INVENTION

Various different types of sealable protective bag are known for use in protecting articles from damage by liquids, such as rain or flood water. Such bags are made from a variety of materials, including flexible plastics materials and may include check valves to allow the egress of trapped air whilst resisting the ingress of liquids, such as water. Examples of such bags are disclosed in GB Patent Application Publication No. 2,350,347 (Iftkhar), US Patent Application Publication No. 2005/0025396 (ErkenBrack), International Patent Application No. PCT/US93/09398 (Theis), and US Patent Application Publication No. 2003/0234202 (Anderson).

However, such bags are sealed in only a limited number of ways. Bags which use zippered seals are common and relatively easy to use, but often fail when exposed to extreme conditions, such as the conditions found during floods. One zipper technology, which uses a pressure difference between the interior and exterior of the bag to enhance the seal, is described in US 2005/0025396 (ErkenBreck). Simple prior art closures, such as those depicted in FIG. 20, are popular with package producers as they are inexpensive and easy to use and provide the contents with reasonable protection from the elements, such as moisture, rain or snow. A bag or container 72 comprises flexible sheets 74, 75 which function as side walls. Side wall 74 extends beyond the aperture to form a protective cover 76 for the aperture, of a length which allows it to overlap an adhesive strip 78 adhered to sheet 75 and protected with a release liner. The cover 76 is then adhered to close the aperture by removing the release liner and bringing the cover into contact with the adhesive, and then pressing the flexible sheets and protective cover together. This sealing mechanism is easy to use and, because it is not an air tight seal, it allows air to be evacuated from the interior of the container. However, it is not waterproof.

Other sealable bags are disclosed in FR 2,885,353 (Allegre), US 2003/0059132 (Vetter) and U.S. Pat. No. 5,711,751 (Harmanoglu). These bags include release liners which protect an adhesive layer, but which extend out of the bags. Thus, the release liners may be damaged before use. US 2004/0013322 (Taylor) discloses a sealable bag in which both a release liner and adhesive layer are formed on the same flexible sheet, which extends between the release liner and the opposed flexible sheet, leading to a risk that the release liner and adhesive layer will be accidentally separate before use and increasing the bulk of the sealable aperture of the bag. The bag disclosed in US 2004/0013322 can only be made by depositing a release liner material with jet printing and could not be cost-effectively made using strips of preformed release liner material. Some embodiments of the invention aim to provide improvement to these sealable bags.

The present invention aims in general to provide an improved protective container which can be cost-effectively manufactured. The invention aims to provide a protective container with an aperture which can be effectively sealed. Some embodiments aim to provide a protective container which is designed in a fashion which allows a strong single-use adhesive to be employed conveniently and effectively to form a good seal. Some embodiments aim to provide a protective container which minimises the risk that the release liner will be damaged before use.

The invention may be used to protect articles such as personal effects, emergency supplies, valuable documents etc., from water damage, due to acts of God such as hurricanes or floods. The invention may be useful for general packaging, courier and postal services etc. where it is desirable to protect articles for a period of time appropriate to the intended use.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention there is provided a protective container comprising a sealable aperture defined by opposing first and second flexible sheets which are joined to each other by seals at either side of the aperture, such that the aperture is closable by bringing the first and second flexible sheets into contact with each other across the width of the aperture, wherein the inward facing surface of the first sheet comprises an adhesive strip which extends across the width of the aperture and is covered by a release liner such that when the release liner is removed, the aperture is sealable by bringing the adhesive strip into contact with an opposing part of the second flexible sheet across the width of the aperture, wherein the release liner does not extend into the seal between the first and second flexible sheets at either side of the sealable aperture.

Because the release liner does not extend into the seal between the first and second flexible sheets, the release liner can be more readily removed that would otherwise be the case.

Preferably, the release liner does not extend into the seal between the first and second flexible sheets at either side of the sealable aperture because the release liner does not extend to the seal between the first and second flexible sheets at either, or preferably both, sides of the sealable aperture. Thus, the release liner can be more readily removed than if it extended to the seal between the first and second flexible sheets at either, or preferably both, sides of the sealable aperture. Typically, the release liner does not extend to the edge of the adhesive strip at one or both sides of the aperture. However, the release liner preferably extends across at least 80%, 90%, 95%, 97% or 99% of the way between the seals between the first and second flexible sheets.

Preferably, the release liner lies wholly within the protective container. This reduces the risk of damage to the release liner. Preferably, the release liner faces directly onto the second flexible sheet. This contrasts with the arrangement in US 2004/0013322 where a release liner on a first flexible sheet does not face directly onto the opposed second flexible sheet.

Preferably, the release liner comprises a folded back end portion which forms a tab by means of which the release liner can be gripped. Preferably, the total length of the release liner, including the folded back end portion (i.e. the distance across which the release liner would extend if the folded back end portion was straightened out and the release liner was extended to its maximum length), is greater than the length of the adhesive strip. More preferably, the total length of the release liner, including the folded back end portion (i.e. the distance across which the release liner would extend if the folded back end portion was straightened out and the release liner was extended to its maximum length), is greater than the width of the protective container. Release liner portions may be applied directly to adhesive strips from a cassette of such release liner portions.

The aperture will typically be sealable in a watertight fashion by bringing the adhesive strip into contact with an opposing part of the second flexible sheet across the width of the aperture. The protective container will typically be waterproof so that, when the aperture is sealed, the protective container is watertight. The protective container is typically a protective bag.

The adhesive strip may extend into the seal between the first and second sheets at either, or preferably both, sides of aperture. However, as the release liner does not extend into the seal between the first and second flexible sheets at either side of the sealable aperture, the or each release liner can be readily removed. The adhesive strip may extend through the seals to the very edges of the first and second sheets. The first and second sheets may be sealed to each other on either side of where the adhesive strip extends through the seals. The edge of the adhesive strip which extends through the seal between the first and second sheets may be covered by a protective layer.

The adhesive strips may be formed from a reusable adhesive. However, the adhesive strips are preferably formed from a single-use adhesive. Thus, a stronger adhesive might be used than if it were necessary to provide a multiple-use adhesive. Typically, in order to open the container, the flexible sheets must be cut across the width of the aperture, such as to remove the portion which has the seal formed by the sealed adhesive strip.

A plurality of the said adhesive strips, each of which extends across the width of the aperture, may be provided on the inward facing surfaces of the flexible sheets. The adhesive strips, are typically covered with a release liner as described above.

Thus, a protective container may be formed with a plurality of rows of adhesive strips, which enables the container to be sealed once per adhesive strip, such that the flexible fabric is cut off below (i.e. on the side furthest from the aperture) the sealed adhesive strip, but above the next adhesive strip, so that the bag may be reused the same number of times that there are adhesive strips provided.

The first and second flexible sheets may be joined to each other by seals formed by adhesive, welding (e.g. heat welding, ultrasonic welding, hot wedge welding) or any other permanent joining technique.

We include the possibility that the first and second flexible sheets could be formed from a single piece of single-layered or multi-layered material which is folded such that the first and second flexible sheets are formed by different regions of the same piece of material.

The first flexible sheet may comprise an elongate reinforcement member which is parallel to, and typically overlays, the adhesive strip. Typically, the second flexible sheet comprises a further, opposing, elongate reinforcement member. The or each elongate reinforcement member may be attached to the material which forms the bulk of the first and second flexible sheets. The or each reinforcement member may be in the form of layer laminated to the material which forms the bulk of the flexible sheets. The or each elongate reinforcement member may abut the material which forms the bulk of the flexible sheets. The aperture may be defined by opposed elongate reinforcement members. Opposed elongate reinforcement members may define the sealable aperture of the protective container. Preferably, opposed elongate reinforcement members are sealed to each other at either side of the aperture. Preferably, the or each elongate reinforcement member does not wrinkle, in contrast to thin, highly flexible, sheets of plastics material. Preferably, the or each elongate reinforcement member is substantially flexible about a transverse axis (i.e. an axis parallel to its or their width) and resists transverse movement (e.g. of the centres of each elongate reinforcement member) relative to each other, so as to aid alignment of the adhesive strip when they are brought into contact with each other to seal the aperture. For example, the or each elongate reinforcement member may be made from a material which is stiffer that the bulk of the flexible sheets. The or each elongate reinforcement member may be at least 4 times broader than they are thick, thereby flexing much better about a transverse axis than an axis which is normal to their major surface. Typically, the or each elongate reinforcement member has a length (across the width of the aperture) which is more than 4 times its or their width. The or each elongate reinforcement member may comprise a strip of plastics material. By providing elongate reinforcement members which resist transverse movement relative to each other, the adhesive strip can be more accurately brought into contact with the interior surface of the opposite elongate reinforcement member in a flat and regular manner. This is particularly helpful where the adhesive strips are designed for a single use as a strong adhesive can be used such that the position to which the adhesive strip adheres could not be altered, or could not be altered without compromising the quality of the eventual seal, if it was slightly misaligned and the alignment was corrected, or if the adhesive towards the middle of the first flexible sheet was incorrectly brought into contact with a non-opposing part of the interior of the second flexible sheet.

Opposing elongate reinforcement members may be sealed to each other by elongate heat seals above, below and between the adhesive strips. Such seals preferably do not overlap with the adhesive strips. The release liner may be wider than the adhesive strips and the elongate heat seals may extend to where the release liners begin.

Preferably, the interior surfaces of the first and second flexible sheets comprise cooperating opposed keying members, such that a first keying member (e.g. a protrusion) on the first flexible sheet may be fitted into a second keying member (e.g. a corresponding recess) on the second flexible sheet to align the first and second flexible sheets relative to each other. This facilitates the correct alignment of the sheets to obtain a good seal. This is particularly helpful where an adhesive strip is designed for a single use as a strong adhesive can be used such that, once an adhesive strip has been brought into contact with the opposing region of the second flexible sheet, the adhesive strip could not be detached, or could not be detached without compromising the quality of the eventual seal, if it was slightly misaligned or wrinkled. When used in combination with the elongate reinforcement members, this provides a practical method of ensuring that the adhesive strip is smoothly and correctly fitted to the inner surface of the opposite flexible sheet. Typically, a keying member is located proximate to an adhesive strip on the side towards the interior of the protective container. The keying members should be sealed to the surrounding flexible sheets in a water proof fashion. The keying members may be formed in the elongate reinforcement members. The keying members may be formed in the material which makes up the bulk or all of the first and second flexible sheets.

The interior surfaces of the first and second flexible sheets may comprise cooperating opposed elongate gripping members, which extend across the sealable aperture and which can be detachably mated to form a waterproof seal. Co-operating opposed elongate gripping members which function, like zips, to detachably seal bags made from plastics, are known to those skilled in the art. Typically, the opposed elongate gripping members will be located inwards of the adhesive strip. Typically the opposed elongate gripping members are parallel to the adhesive strip. The co-operating opposed elongate gripping members can therefore provide an additional seal, which is supplementary to the seal formed using the adhesive strip, and can also help to align the first and second flexible sheets, proximate to the adhesive strip, to facilitate the formation of a good seal using the adhesive strip.

The protective container is preferably of variable internal volume, for example the protective container is typically a protective bag. Preferably, the protective container comprises a check valve configured to allow air from within the container to be evacuated but to resist the ingress of liquid (such as water) on the outside of the container. Thus, the container can typically be sealed and then air within the container can be evacuated through the check valve. Otherwise, unless sufficient air was removed before the protective container was sealed, the protective container might float due to the buoyancy arising from the sealed air.

The first and second sheets may be made from a material such as impermeable polyethylene, polypropylene, PET, vinyl, nylon or treated paper.

The protective container may comprise a flexible tube having a first end and a second end, each of which comprises an aperture, wherein the second end is fixed within the protective container such that the tube opens into the interior of the protective container and the flexible tube is extendable from a stowed position within the protective container to a deployed position in which the first end extends through the sealable aperture of the protective container. The flexible tube may be adapted to be rolled up within the protective container. The flexible tube may comprise a plurality of inflexible or relatively inflexible tube members which are flexibly joined to each other.

The protective container may be formed from a generally tubular flexible material arranged as a flat tube with folds at either side. The first and second flexible sheets may be formed by further opposed sheets which are sealedly attached to one end of the flat tube. The first and second flexible sheets may be opposed faces of the generally tubule flexible material which have been cut and resealed at either side, after the addition of the adhesive strip and release liner, to form a sealable aperture therebetween.

The idea of providing a plurality of single-use adhesive strips, each of which extends across the aperture is applicable to other types of protective container and, accordingly, the invention extends in a second aspect to a protective container comprising a sealable aperture defined by opposing first and second flexible sheets which are joined to each other by seals at either side of the aperture, such that the aperture is closable by bringing the first and second flexible sheets into contact with each other across the width of the aperture, wherein the inward facing surface of the first sheet comprises a plurality of single-use adhesive strips, each of which extends across the width of the aperture and is covered by a release liner such that when the release liner is removed, the aperture is sealable by bringing the adhesive strip into contact with an opposing part of the second flexible sheet across the width of the aperture.

Thus, after a first adhesive strip (located towards the opening of the container) has been used to seal the aperture, the portion of the first and second flexible sheets which includes the sealed first adhesive strip can be cut off, leaving a protective container with one or more further adhesive strips, enabling the protective container to be reused.

Further optional and preferred features correspond to those discussed in relation to the first and fourth aspects of the invention.

According to a third aspect of the present invention there is provided a protective container comprising a sealable aperture defined by opposing first and second flexible sheets which are joined to each other by seals at either side of the aperture, such that the aperture is closable by bringing the first and second flexible sheets into contact with each other across the width of the aperture, wherein the inward facing surface of the first sheet comprises an adhesive strip which extends across the width of the aperture and which is covered by a release liner such that when the release liner is removed, the aperture is sealable by bringing the adhesive strip into contact with an opposing part of the second flexible sheet across the width of the aperture, wherein the flexible sheets each comprise opposed elongate reinforcement members which are parallel to (and preferably overlay) the adhesive strip provided on the first flexible sheet.

Preferably, the opposed elongate reinforcement members are sealed to each other at either side of the aperture. Preferably, the elongate reinforcement members are substantially flexible about a transverse axis (i.e. an axis parallel to their width) and resist transverse movement relative to each other, so as to ensure that the adhesive strip is fitted flat to the interior surface of the second sheet, in the correct location, to seal the aperture. For example, the elongate reinforcement members may comprise members which are stiffer that the bulk of the flexible sheets and which have a length (across the width of the aperture) which is more than 8 times their width. The elongate reinforcement members may comprise strips of plastics material.

Further optional and preferred features correspond to those discussed in relation to the first and fourth aspects of the invention.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a protective container in which first and second sheets of material are brought together on a continuous basis and cut to form protective containers, wherein the first sheet of material comprises one or more continuous rows of adhesive proximate to a sealable aperture end of the resulting protective containers on the face which is brought into contact with the second sheet of material, and wherein the first and second sheets of material are sealed along a dividing line which defines divisions between successive protective containers, except where the adhesive strips cross the dividing line, and are simultaneously or subsequently cut along the dividing line to form protective containers.

The adhesive strip may be made from a material which would be adversely affected by heat sealing and an elongate heat seal may be formed above, below and, where there are more than one adhesive strip, between, the or each adhesive strip, in a region which extends across the dividing line between successive protective containers. Preferably, the elongate heat seals will not extend into the adhesive strip. The elongate heat seals will typically be elongate parallel to the adhesive strips, which are parallel to the direction of movement of the sheets of material. The method may comprise the step of subsequently applying pressure to the region of the adhesive strips between the elongate heat seals, to force adhesive partially outwards. Sections of release liner may be provided periodically along the length of the adhesive strips, with gaps at the dividing line between protective containers. Preferably the sections of release liner are located such that they do not extend into the seal formed between successive protective containers. The sections of release liner may be formed by periodically cutting the continuous release liner on a continuous adhesive strip which already has release liner applied thereon. The sections of release liner may be formed by applying separate sections of release liner periodically to adhesive strip, optionally after the step of removing a continuous release liner which is already present on the adhesive strip. An adhesive strip may be used which has a first adhesive surface having separate sections of first release liner located in contact with the first adhesive surface and spaced apart along the length of the adhesive tape, and a continuous second release liner which extends along the tape in contact with the first release liners and the adhesive surface between first release liners. In use, the continuous second release liner can be pealed off on a continuous basis, revealing the first adhesive surface and sections of first release liner provided periodically along the length of the adhesive strip. The adhesive strip will typically be double sided.

The first and second sheets of material may comprise a flexible film (composed of one or more layers of flexible material) which forms the bulk of the side walls of the resulting protective container. Either or both of the first and second sheets of material may be formed from a sheet of flexible film which is folded back on itself to form a container with one or more double layered walls. The first and second sheet forming sections of material may each comprise an elongate strip of less flexible material, which is less flexible than the film which forms the bulk of the side walls, located at or near the sealable apertures of the resulting protective containers and the method may comprise the step of sealing the elongate strips of the first and second sheet forming sections of material. Where the adhesive strips are made from a material which would be adversely affected by heat sealing, the seal between strips of less flexible material preferably does not extend across the adhesive strip or strips. Either or both of the first and second sheets of material may comprise a plurality of layers of flexible material. The first and second sheets of material may be unwound from rolls of material. The first and second sheets of material may be the regions on either side of a fold line of a folded (single ply or multiple ply) sheet of material. The first and second sheets of material may be separated by separating the regions on either side of a fold line of a single folded sheet of material provided on a roll.

Further optional and preferred features correspond to those discussed in relation to the first three aspects of the invention.

According to a fifth aspect of the present invention there is provided a method of manufacturing a protective container in which first and second sheets of material are brought together on a continuous basis and cut to form protective containers, wherein the first sheet of material comprises one or more continuous rows of adhesive proximate to a sealable aperture end of the resulting protective containers on the face which is brought into contact with the second sheet of material, wherein the method comprises the step of applying discrete sections of release liner to the adhesive prior to sealing the first and second sheets of material together.

Preferably, the release liner is cut from a continuous strip (e.g. a roll) of release liner. This allows greater choice of release liner than would be the case if the release liner had to be deposited by a printing technique.

Preferably, each section of release liner comprises a folded back flap. Preferably, the total length of each section of release liner, including the length folded back end portion, is greater than the width of the sealable aperture of the resulting protective container.

The sections of release liner may be dispensed onto the one or more continuous rows of adhesive from a cassette of release liners. The release liners may be stamped onto the one or more continuous rows of adhesive.

Further optional and preferred features correspond to those discussed in relation to the first four aspects of the invention.

According to a sixth aspect of the invention there is provided an adhesive strip comprising a first adhesive surface having separate sections of first release liner located in contact with the first adhesive surface and spaced apart along the length of the adhesive strip, and a continuous second release liner which extends along the strip in contact with and covering the first release liners and the adhesive surface between first release liners. The adhesive strip will typically be double sided. The adhesive strip will typically be a roll of adhesive tape.

Preferably, each section of first release liner comprises a folded back flap. Preferably also, the total length of each section of release liner, including the length of the folded back end portion, is greater than the relative displacement of successive sections of release liner.

Further optional and preferred features correspond to those discussed in relation to the first five aspects of the invention.

DESCRIPTION OF THE DRAWINGS

An example embodiment of the present invention will now be illustrated with reference to the following Figures in which:

FIG. 1 is an isometric projection of the sealable aperture of a flexible protective container in an open position to receive the article or articles which are to be protected;

FIG. 2 is a front elevation of the flexible container, illustrating the main elements;

FIG. 3 is a detail of a section through cut line 11 depicting the container's sealable aperture in an open position;

FIG. 4 is a detail of a section through cut line 11 depicting the sealing of the container's sealable aperture using an adhesive strip;

FIG. 5 is a detail of a section through cut line 11 depicting the container's sealable aperture in an open position after it has been opened once before by cutting along line 54;

FIG. 6 is a sectional detail through cut line 11 depicting the sealing of the container's sealable aperture using an adhesive strip;

FIG. 7 is a schematic view of a production line illustrating the mechanism by which both walls of the flexible container are brought together;

FIG. 8 is a front elevation of the continuous film after it has passed rollers 46 and 48, facing sidewall film 4 and elongate member 2;

FIG. 9 is an elevation detail of a partially completed container after the first step of a process of manufacturing the side edges of the flexible container;

FIG. 10 is an elevation detail of a partially completed container after the second step of a process of manufacturing the side edges of the flexible container;

FIG. 11 is an elevation detail of a partially completed container after the third step of a process of manufacturing the side edges of the flexible container;

FIG. 12 is a sectional detail of the container during the manufacturing method of FIGS. 7 to 11, showing the interior of two adjacent containers at the sidewall edge 38 (elongate member and side wall film not shown);

FIG. 13 is a front elevation of the flexible container indicating the position of the protective elements 42;

FIG. 14 is an elevation detail of a possible adhered position of protective elements 42;

FIG. 15 is an elevation detail showing an alternative embodiment of the flexible container with a side wall formed by a different method;

FIG. 16 is a section detail of the alternative container of FIG. 15, illustrating the inside of two containers at the side wall edge 38 (elongate member and side wall film not shown);

FIG. 17 is an elevation detail of a further alternative embodiment of a protective container of FIGS. 15 and 16, showing possible locations of keys 60 on the elongate members;

FIG. 18 is a section detail taken from cut line 64 depicting the container's sealable aperture in an open position showing one adhesive strip and keys 58 and 60 disengaged from each other;

FIG. 19 is a section detail through cut line 64 depicting the container's sealable aperture in an open position, showing one adhesive strip and keys 58 and 60 disengaged from each other;

FIG. 20 is a front elevation of a plurality of containers according to an alternative embodiment, which remain attached to each other prior to separation;

FIG. 21 is a front elevation of a single container formed from the containers of FIG. 20, following a separation stage;

FIG. 22 is a section detail through a an alternative embodiment of a flexible protective container including additional interlocking keys, shown with the aperture in its open position;

FIG. 23 is a section detail through the protective container of FIG. 22, after sealing;

FIG. 24 is sectional elevation of an embodiment in which protective flaps extend beyond the top of the sidewall seals;

FIG. 25 is a transverse section cut along 218 showing the container of FIG. 24 with protective flaps folded down to protect the adhesive strip whilst liquids are introduced into the container;

FIG. 26 is a sectional elevation of the protective container of FIG. 24 with the flaps folded upwards, the release liner removed and the container sealed using the adhesive strip which is thereby revealed;

FIG. 27 is an elevation detail of a variant of the protective container of FIG. 24 in which the flaps are narrower than the width of the protective container at the location of the adhesive strip and release liner;

FIG. 28 is sectional elevation of a variant of the protective container of FIG. 24, including a retractable tube, shown in an extended configuration;

FIG. 29 is a sectional elevation of the protective container of FIG. 28, in which the flaps are folded down to protect the adhesive strip and release liner and the retractable tube is stowed;

FIG. 30 is a transverse section of the protective container of FIG. 28, along cut line 178, with the flaps folded down and the retractable tube extended;

FIG. 31 is a sectional elevation of the protective container of FIG. 28, in a sealed state, after loading, sealing and re-extending the flaps;

FIG. 32 is a sectional elevation of a variant of the protective container of FIG. 28, including a flexible retractable tube arranged to roll up, in a sealed state, after loading;

FIG. 33 is a section elevation of a variant of the protective container of FIG. 28, including a retractable tube formed by flexibly hinged tube members, in a sealed state, after loading;

FIG. 34 is a transverse section along cut line 272 of a protective container formed from a tube of flexible material;

FIG. 35 is a front elevation of the protective container of FIG. 34;

FIGS. 36 and 37 are front elevations of a protective container with a narrow neck;

FIG. 38 is a perspective view of apparatus for constructing a plurality of containers from two separate sheets of sidewall film, using a printing method to apply release liners;

FIG. 39 is an elevation detail of the manufacturing apparatus of FIG. 38;

FIG. 40 is a front elevation of the manufacturing apparatus of FIG. 38;

FIG. 41 is an elevation detail of alternative manufacturing apparatus;

FIG. 42 is a front elevation of the manufacturing apparatus of FIG. 41, adapted to manufacture a plurality of containers; and

FIG. 43 is a perspective view of alternative apparatus for manufacturing protective containers, which employs a single sheet of film which is a folded to form opposite side walls of the protective container.

DETAILED DESCRIPTION OF AN EXAMPLE EMBODIMENT

With reference to FIGS. 1 to 10, a flexible protective bag is comprised of flexible plastic side walls 4, 8, each of which is sealedly attached to thicker, less flexible elongate reinforcement members 2, 6 (functioning as elongate reinforcement members) which define the aperture of the protective bag and which are sealed to each other at either end. A side wall and the attached elongate reinforcement member function as a flexible sheet. Two adhesive strips 14, 16 on the interior of the elongate reinforcement members each extend across the entire width of the aperture of the protective bag. Each is covered with a continuous release liner 18, 20 which protects the adhesive until it is used. The release liner is slightly wider than the adhesive strips and extends along most of the length of the adhesive strips. However, the release liners extend only to just before the place where the adhesive strips pass into the seal between the elongate reinforcement members. The release liners are wholly within the protective bag to reduce the chance that they will be damaged before use. The release liners face directly onto the opposed flexible sheet so that the protective bag is relatively thin.

The elongate reinforcement members are flexible around an axis transverse to their length, so that the container can be easily opened before it is sealed, but are relatively resistant to moving transversely relative to each other. Accordingly, as they are sealedly joined at either end, they will tend to remain in close alignment with each other when they are pressed together to close the aperture. This facilitates accurate locating of the adhesive strips and avoids the risk that the resulting seal will not be watertight due to gaps, wrinkles, or accidentally bringing a part of the adhesive strip into contact with a part of the interior surface of the other elongate reinforcement member which is not directly opposed. This also facilitates the formation of a good seal between the elongate reinforcement members.

In use, the centres of the elongate reinforcement members are parted, to open the aperture. Articles to be protected are introduced into the protective bag through the aperture. The strip of release liner is removed from the outermost adhesive strip and the elongate reinforcement members are brought together, bringing the adhesive strip into contact with the interior surface of the opposing elongate reinforcement member of the opposing flexible sheet. Because the elongate reinforcement members resist lateral relative movement (which would require them to bend in the plane of the elongate reinforcement members) and are sealed to each other at either end, wrinkling is avoided and the adhesive strip is adhered to the correct opposing location. The resulting sealed protective container is waterproof. The adhesive is single-use and gives a strong waterproof seal.

In order to remove the contents, the outermost adhesive strip is cut off. The contents of the protective bag can thereafter be removed. The protective bag can then be inspected and checked for any tears and, if none are found, reused by forming a seal using the second adhesive strip.

FIG. 7 illustrates a production machine for manufacturing protective bags. First flexible sheet forming material 3, from a roll, has been preformed with an elongate reinforcement member 6 sealedly attached to a plastic side wall of the bag 4. Two continuous parallel adhesive strips 14, 16 are attached along the length of the elongate reinforcement member. Each adhesive strip is covered with discontinuous lengths of release liner 18, 20 which have periodic gaps. The release liners 18, 20 comprise tabs 22, 24 to make them easier to grasp and remove. The tabs are formed by folding back an end of each release liner. Alternatively, separate tab members could be joined to strips of release liner.

A second flexible sheet forming material 5, from a roll, also comprises an elongate reinforcement member 2 attached to the plastic side wall of the bag 4 along the length of the elongate reinforcement member. The second flexible sheet passes between rollers 50 and 52 and is brought into alignment and contact with the first flexible sheet between rollers 46 and 48.

The protective bags are now finished by a sealing and cutting procedure illustrated in FIGS. 8 to 11. First, a conventional heat sealing station including a master seal bar which imparts an elongate heat seal 40 along the base 39 of the flexible sheets. The first and second flexible sheets are also heat sealed together in a line extending from the base of the flexible sheet forming materials to where the side walls meet the elongate reinforcement members, producing a heat seal 30 which defines the interface between successive protective bags. A further heat sealing station forms elongate seals 32, 34, 36, which are parallel to the length of the elongate reinforcement members (i.e. parallel to the rim of finished bag) above, below and between the adhesive strips, in the space which is not covered by either the adhesive strips or the release liners (which are slightly wider than the adhesive strips).

Thereafter, an unheated bar presses the area of adhesive strips which are not covered by the release liners. This has the effect of compressing the adhesive strips and squeezing the adhesive to the edges, against the heat sealed regions, improving the water-tightness of the eventual seal.

Next, individual protective bags are separated by cutting the mutually sealed sheet forming materials down the centre line 38 of the midline between the bags, transverse to the direction of movement of the strips of material. This bisects the heat seal between the side walls and the elongate heat seals above, below and between adhesive strips. However, a region of the adhesive strip is exposed to either side of the resulting protective bag. The ends of the adhesive strip may optionally be protected with tape, or a seal made from plastics material 42, which is wrapped around the edges of the elongate reinforcement members where the adhesive strips are exposed, and sealed.

The above method is especially suitable where the adhesive strip is made from a material which has properties that would be adversely affected, such as to damage the waterproof nature of the resulting seal, or to significantly affect the longevity and/or resilience of the seal, by a conventional bag manufacturing procedure in which a dividing line between adjacent bags is heat sealed along its entire length and subsequently or simultaneously bisected.

FIGS. 15 and 16 illustrate an alternative embodiment which may be used where the adhesive strip is made from a material that is not adversely affected by heat sealing. In this embodiment, adjacent protective bags are sealed and separated by a single heat seal and single cut which extends up the entire sides of the protective bags. This might be achieved using a heat sealing step followed by a cutting step, or by a combined heat sealing and cutting step, for example using known hot wire procedures.

The first flexible sheet 3 can be manufactured by a procedure in which a sheet of relatively stiff material which functions as the elongate reinforcement member is attached by a continuous heat sealing/welding process to the layer, or layers, of material used to form the first side wall. Alternatively, adhesive may be used continuously along the sheet of relatively stiff material to attach the sheet of relatively stiff material to the layer, or layers, of material used to form the first side wall. Adhesive tape can be applied continuously to the elongate reinforcement members. For example, adhesive tape which is already covered on one side during its original manufacturing process by a release liner may be applied along the length of the elongate reinforcement members, such as to leave the release liner facing outwards, away from the elongate reinforcement member. The release liner may be precision cut periodically to leave gaps, forming the flexible sheet shown in FIG. 7. Alternatively, the release liner supplied with the adhesive tape may be removed continuously along its length and new release liners may be applied, with gaps therebetween, on a continuous basis, again forming the flexible sheet shown in FIG. 7. Alternatively, an adhesive tape may be used which has a first adhesive surface having separate sections of first release liner located in contact with the first adhesive surface and spaced apart along the length of the adhesive tape, and a continuous second release liner which extends along the tape in contact with and covering the first release liners and the adhesive surface between first release liners. In use, the continuous second release liner can be peeled off on a continuous basis, again forming the flexible sheet shown in FIG. 7. Tabs 22, 24 which assist the user in removing the release liner may optionally be applied to each section of release liner.

Optionally, cooperating opposed keying members may be provided as illustrated in FIGS. 17 to 19. Opposing elongate reinforcement members on opposing elongate reinforcement members may comprise cooperating formations, for example a protrusion on one face and a cooperating recess on the opposite face. The keying members are located close to an adhesive strip, on the side of the adhesive strip located towards the interior of the protective container. The user can locate the protrusion in the corresponding recess, to further enhance the correct alignment of the elongate reinforcement members when the protective bag is sealed.

In an alternative embodiment, each flexible sheet may be made from one or more layers of material. In an alternative embodiment, the elongate reinforcement members are formed as a layer on the material which makes up the side walls of the protective bag.

With reference to FIGS. 20 and 21, an alternative embodiment 174 uses discontinuous release liners 22, at least one end of which is folded back to form a tab which can be grasped by a user. The folded back portion is shown as being at an outwardly extending angle to the adhesive strip for clarity of representation but is preferably folded such that the strip of release liner doubles back on itself and extends back along the length of the adhesive strip. Note that in FIGS. 20 and 21, the length of each strip of release liner is greater than the width of the protective container. This arrangement could not have been achieved by cutting and folding a strip of release liner which was of the same length as the adhesive strip which it overlays, for example, a strip of release liner formed by laying a tape comprising adhesive strip with strips of overlaid release liner along the flexible sheets which are to form a plurality of containers, and cutting the release liner between containers. In this embodiment, the strips of release liner extend outside the rim of the bag.

Each wall of the protective container illustrated in FIGS. 20 and 21 is formed by folding a single sheet of plastics film at fold line 180. The resulting walls 152 are thereby formed by two layers of plastics film which have been folded back on themselves, sealed down seal line 192 and cut along cut line 195.

FIGS. 22 and 23 illustrate a variant including interlocking keying members 224, 226 on opposite side walls 220, 222. In contrast to the embodiment illustrated in FIGS. 17 to 19, the keying members are formed in the material which forms the majority of the first and second flexible sheets, rather than in an elongate reinforcement member. Line 228 illustrates the location where the walls of the protective container should be cut, below the seal, to open the bag.

An alternative protective container illustrated in FIGS. 24 to 26 includes flaps 181, 182 in the first and second flexible sheets, which extend beyond the sealable aperture of the bag. One flap is an extension of the flexible sheet to which the adhesive layer and release liner are attached. The other flap is an extension of the opposite flexible sheet. The flaps can be folded down, as illustrated in FIG. 25, 186, 188, to protect the adhesive strip and release liner where it is desirable to introduce a liquid or dirty material into the container, which might otherwise damage the adhesive strip and/or release liner. The protective containers illustrated in FIGS. 24 and 25 can be made by folding a single sheet of material into two and forming a heat seal 192 between successive protective containers, which extends to an end point 198 which is spaced apart from the top edge 183 of the first and second sheets. The sealable aperture of the protective container is defined by the first and second flexible sheets and the ends of the heat seals 192 therebetween. Successive protective containers are subsequently or simultaneously divided by cutting along cut line 195. Alternatively, a flap which extends beyond the sealable aperture of the protective container may be provided on only one of the first and second sheets. A further variation is illustrated in FIG. 27, where the first and second flexible sheets have been cut away so that the flaps are narrower than the width of the protective container at the level of the adhesive strip and release liner. In this embodiment, the flaps are easier to fold down into the container.

FIGS. 28 through 31 illustrate a protective container 177 which includes a flexible tube 200 having an open first end 210 which is internal to the container and an open second end 204 which can be deployed outside the protective container such that the flexible tube can be extended from a stowed position within the protective container to a deployed position in which it extends through the sealable aperture of the protective container. The flexible tube is attached to one of the walls of the protective container using heat seals 212. The flexible tube can be used to conveniently introduce liquids or particulate materials into the interior of the protective container without damaging the adhesive strip and release liner.

FIG. 32 illustrates a variant including a flexible tube 206 which can be unrolled along its length. FIG. 33 illustrates a variant in which a flexible tube 208 is formed by a series of rigid but flexibly jointed tube members 203. In FIGS. 32 and 33, the containers are shown sealed, after loading, with the flexible tubes in the stowed position.

With reference to FIGS. 34 and 35, a protective bag 229 can be formed from a tube of flexible plastics material 230 such that the edges which join the sheets of material which make up the bulk of the opposed walls of the bag 231, 232 are folds rather than seals. This has the advantage that the resulting protective bag is more comfortable to grip. In this embodiment, the first and second flexible sheets which are joined to each other by seals at either side of the aperture are formed by sheets of plastics material 234, 236 which define the sealable aperture of the bag, which may be as flexible as the material which makes up the bulk of the front and back walls of the bag, or may be less flexible. An adhesive strip 258 extends across the width of the aperture of the bag, into the side seams 234, 236. Release liner 259 covers the adhesive strip. The lower edges 243, 244 of the sheets which define the sealable aperture extend below the upper edges 232 of the sheets which make up the bulk of the opposed walls of the bag. A heat sealed weld 241 sealedly joins a first sheet which defines the sealable aperture of the bag to a first sheet which makes up the bulk of a wall of the bag. A second heat sealed weld 242 sealedly joins a second sheet which defines the sealable aperture of the bag to a second sheet which makes up the bulk of the other wall of the bag. In order to form these seals without sealing the first and second sheets together, a sheet of heat resistant material, such as polytetrafluoroethylene is temporarily introduced between the first and second sheets. The sheets which form the sealable aperture of the bag are welded together to form welds 246, 248. A further seal 254 is provided at the end of the tube of flexible plastics material which is opposite the sealable aperture.

In an alternative embodiment, a protective bag can be formed from a tube of flexible material which is formed into a flat structure with fold lines at either side, by slitting a first end of the tube at the end which is to form the sealable aperture, and peeling back opposite sides of the tube of flexible material. An adhesive strip and release liner can then be applied to the resulting flaps which are then sealed together at either edge.

With reference to FIGS. 36 and 37, in a further embodiment which is particularly suitable for the storage of liquids and particulate materials, a protective bag 261 has a sealable aperture on a neck which is significantly narrower than (e.g. less than half the width of) the widest part of the protective bag. Protective bags with the narrow neck can be formed from continuous sheets of flexible material or a folded sheet of flexible material, by using seals and cut lines which are not parallel to the length of each bag but are arranged to cut out a portion of flexible material between consecutive protective bags, leaving the relatively narrow neck and sealed aperture. A portion of the edge seal 264 is generally parallel to the base of the protective bag.

FIGS. 38 through 40 illustrate manufacturing apparatus 132 for manufacturing a plurality of protective containers from first and second rolls of plastics film 102, 100. A level substrate 130 supports a first roll of side wall film 102 and an adhesive roll, which includes two separate strips of adhesive, covered with a parent release liner. The adhesive strips are applied to side wall film from the roll and pressed into place with a compression roller 120. The parent release liner is then rolled up onto a retrieval roll 106. Pre-prepared strips of release liner 108 with ends which have been folded back to form tabs are arranged in a stack 136 within a release liner container 124, which includes a pressing member 126, such as a weight, to press the strips of release liner downwards. The strips of release liner are then stamped down onto the adhesive strips using a stamping mechanism. A first roller 110 guides each strip of release liner out from the release liner container to a second roller 114. Each strip of release liner is retained by a keying member 140 which is briefly withdrawn periodically to engage the next strip of release liner

A vacuum nozzle 116, briefly retains a strip of release liner whilst it is moved down, onto an adhesive strip, in a stamping motion, under the control of a moveable housing 112.

The first roll of side wall film is transported along a further flat substrate where it is brought into contact with the second side wall film 4 from a roll 100, guided between feed rollers 122, heat sealed using heat seal bars 118, and simultaneously cut to separate the protective containers using a cutting mechanism 128.

FIGS. 41 and 42 illustrate alternative manufacturing apparatus 138. In the alternative apparatus, the release liner container 160 includes a compression mechanism 164 which presses down upon a stack of release liners 108, which are guided by a compression mechanism which directs the strips of release liner out of the bottom of the stack onto the adhesive strips. The compression mechanism moves between a disengaged position 144 and a compressing position 146, which causes it to compress and guide the stack of strips of release liner. In FIG. 41, the release liner is shown in an unengaged position. In use, the container will be moved downwards to an engaged position 162, from which release liners can be fed directly onto the adhesive strips.

FIG. 43 illustrates alternative manufacturing apparatus which uses a single sheet of side wall film 150, which is folded along fold line 180. Two opposed portions of the side wall film are separated using guide rollers 170 and 172. The first portion 154 has adhesive strips and release liners applied thereto as before. The second portion 152 forms the opposite wall of the resulting protective container. As the films which form the first and second flexible sheets are attached by fold line 180, there is no need to seal the bottom of the protective containers, and a single combined heat sealer and cutter 166 can be used to seal and separate the protective containers.

Importantly, these procedures have enabled protective bags to be manufactured in which adhesive strips extend the whole way across the sealable aperture of the protective bags. This facilitates the provision of a waterproof seal. Each adhesive strip is covered by a release liner which extends the majority of the way between the seals at either end of the sealable aperture, but which does not extend out of the sealable aperture of the protective bags, reducing the chance of it being damaged before it is used. The length of each release liner, including the length of the folded back end portion, exceeds the width of the sealable aperture. Because the release liners do not extend into the seals, they can be readily removed by a user.

Further modifications and variations may be made within the scope of the invention herein disclosed. 

1.-41. (canceled)
 42. A protective container comprising a sealable aperture defined by opposing first and second flexible sheets which are joined to each other by seals at either side of the aperture, such that the aperture is closable by bringing the first and second flexible sheets into contact with each other across the width of the aperture, wherein the inward facing surface of the first sheet comprises an adhesive strip which extends across the width of the aperture and is covered by a release liner such that when the release liner is removed, the aperture is sealable by bringing the adhesive strip into contact with an opposing part of the second flexible sheet across the width of the aperture, wherein the interior surfaces of the first and second flexible sheets comprise cooperating opposed keying members, such that a first keying member on the first flexible sheet may be fitted into a second keying member on the second flexible sheet to align the first and second flexible sheets relative to each other during sealing.
 43. A protective container according to claim 42, wherein the interior surfaces of the first and second flexible sheets comprise cooperating opposed elongate gripping members, located inwards of the adhesive strip, which extend across the sealable aperture and which can be detachably mated to form a waterproof seal.
 44. A protective container according to claim 42, wherein the release liner lies wholly within the protective container.
 45. A protective container according to claim 42, wherein the release liner faces directly onto the second flexible sheet.
 46. A protective container according to claim 42, wherein the protective container is waterproof when the aperture is sealed.
 47. A protective container according to claim 42, comprising a plurality of the said adhesive strips, each of which extends across the width of the aperture, on the inward facing surface of the first flexible sheet.
 48. A protective container according to claim 42, wherein the or each adhesive strip comprises a single-use adhesive.
 49. A protective container according to claim 42, wherein the first and second flexible sheets are formed from a single folded piece of single-layer or multi-layer material.
 50. A protective container according to claim 42, wherein the first flexible sheet comprises an elongate reinforcement member which is parallel to, and typically overlays, the adhesive strip.
 51. A protective container according to claim 50, wherein the second flexible sheet comprises a further, opposing, elongate reinforcement member.
 52. A protective container according to claim 51, wherein opposed elongate reinforcement members are sealed to each other at either side of the aperture.
 53. A protective container according to claim 50 wherein the elongate reinforcement members are substantially flexible about a transverse axis and resist transverse movement relative to each other, so as to aid alignment of the adhesive strip when they are brought into contact with each other to seal the aperture.
 54. A protective container according to claim 51, wherein the first and second keying members are formed within the elongate reinforcement members
 55. A protective container according to claim 42, wherein the or each adhesive strip extends into the seal between the first and second sheets at either or both sides of the aperture.
 56. A protective container according to claim 55, wherein the or each adhesive strip extends through the seals to the very edges of the first and second sheets, and the first and second sheets are sealed to each other on either side of where the or each adhesive strip extends through the seals.
 57. A protective container according to claim 42 which is a protective bag.
 58. A protective container comprising a sealable aperture defined by opposing first and second flexible sheets which are joined to each other by seals at either side of the aperture, such that the aperture is closable by bringing the first and second flexible sheets into contact with each other across the width of the aperture, wherein the inward facing surface of the first sheet comprises an adhesive strip which extends across the width of the aperture and is covered by a release liner such that when the release liner is removed, the aperture is sealable by bringing the adhesive strip into contact with an opposing part of the second flexible sheet across the width of the aperture, wherein the interior surfaces of the first and second flexible sheets comprise cooperating opposed elongate gripping members, located inwards of the adhesive strip, which extend across the sealable aperture and which can be detachably mated to form a waterproof seal.
 59. A protective container according to claim 58, wherein the or each adhesive strip comprises a single-use adhesive.
 60. A protective container according to claim 58, wherein the first flexible sheet comprises an elongate reinforcement member which is parallel to and overlays the adhesive strip and wherein the second flexible sheet comprises a further, opposing, elongate reinforcement member.
 61. A protective container according to claim 58 which is a protective bag. 